Do you ever not really feel anything sometimes during sex? Like you’re really into it and having a great time but then you can’t really feel his dick in you or you can feel it but it’s not a pleasurable feeling it’s just there?

Like for me if my boyfriend just does basic missionary after a while it’s just a boring feeling and it only feels good if he goes faster and like holds my legs up ygm. Do I get desensitised or something or is it about his size?